Steering Pump Replacement...which one (conical or straight) pls help :)

[Matt_H]

Mechanic has indicated I need to replace my steering pump on my '68 280SL and like other posters here have indicated there are two options (straight or conical) on the pump. As I have read figuring out which one I actually need for my car requires some work with a pulley, and in my mind that creates a bit of a risk that other parts might need to be replaced to put it all back together. Now combining the exploratory work, order the right pump, and then possibly sourcing any additional "new" needs that could be needed to even put the existing pump back in, that could equate to a long time to leave it with my mechanic (not really fair to them as I ask that it be left in the shop and not left outside in the rain  as I just had it detailed.

Is there any way to know which pump I need prior to conducting open heart surgery and taking a look at the existing pump?

Many thanks!

Sorry if I missed it on a thread, I did a search but maybe used the wrong criteria.

[dirkbalter]

Considering you have a later model car, you likely have the conical one if original. The earlier ones are cylindrical.
Not sure what is wrong with your pump, but these are are relatively easy to rebuild if its basic resealing.   

for reference:
https://www.sls-hh-shop.de/main/en/mercedes-230-280sl-w113-/46-steering/46-d-steering-gearbox-fluid-pump

[Matt_H]

Thanks for the very quick response...love the support and help from folks on this board!

I can ask the mechanic...I brought it in as there was a leak and so it might be that yes.

But regardless your best guess is the conical for the 1968? Sorry I have not referenced it is a "later model" before as its a pretty early one in the run so just want to clarify

[dirkbalter]

Not sure about the exact cut off either. You may want to scroll through our pagoda notes. A lot of the model changes are listed there.

[Peter h]

I'm going to change my pump next week. The oil is not only dripping, but already running.
I also have an early 280, they should all be tapered.
Good luck
Peter

[Matt_H]

Good luck with yours!
Please let me know if you do not mind what you find.

When you say tapered, I assume that is the conical correct?

Thanks!

[Peter h]

That's the new pump
Peter

[MikeSimon]

Going out on a limb here, but I think ALL 280SL (M130-983) had the p/s pump with the conical drive shaft.

[Peter h]

I also think that only the early 230sl didn't have a conical pump.
Peter

[mdsalemi]

My 280SL (January 1969 production date) has the conical pump.

[UJJ]

you need this puller to remove the pulley off of the conical shaft

[MartinK]

Please keep in mind that the pump shafts have different thread typres. One has metric pitch and the other has imperial pitch. the imperial pitch could be interchanged with M12x1,25 bit in fact it is 1/2" UNF pitch 20. If you try to wind the wrong nut on the shaft, you will destroy it! Part number metric nut for conical shaft: N 308673 014001, imperial nut UNF for zylindric shaft: A1899900151.

[Peter h]

small update on the power steering pump. The pump was dry and I left it in. The screw at the front of the timing chain came loose and the oil leaked out and spread there. Small mistake, big cause. I don't know why this screw suddenly came loose. The new pump is coming into storage for now.
Peter

I took a picture from the internet.  It's difficult to photograph the place

[lurtch]

I agree with UJJ, you will need a specialized puller.

Also take note: I found that in order to get enough clearance to couple-up the puller to get full travel,
I had to slide the radiator  out of the way.

Larry in CA

[mdsalemi]

Just had my steering pump replaced. (Along with the steering gear box).
As noted my mechanic did have to remove the radiator. Oh while he was at it he may as well change the coolant so he did that. It was probably long overdue. While the car was on the lift, he noticed that one of the pressure sensors on the automatic transmission was leaking. He took it off and sure enough, it was broken and leaking. Got a new replacement from the classic center, but unfortunately it was slightly different than the original one. The threads on the body were not long enough to seat it in the transmission…so the mechanic needed to do a little work on it, basically running a die down the threads to extend them a bit so it would seat and seal.

I realized also that it had been too long since the zerks received grease—so that was done too. While poking around this task he noticed a few issues that we’ll deal with in autumn, mostly some rubber bits needing replacement.

Nice to have a keen set of eyes on the underside. The mechanic is a perfectionist—he’s an engineer for a NASCAR team. Little room for any oversights or errors in his day job!

[Peter van Es]

The mechanic is a perfectionist—he’s an engineer for a NASCAR team.

So your car only turns left now? 

[mdsalemi]

I didn't notice that...but the "revenooers" were chasing me all the way home...and wanted to check my trunk for moonshine.